TW201338238A

TW201338238A - Lithium ion secondary battery, collector constituting negative electrode of lithium ion secondary battery, and electrolytic copper foil constituting negative electrode collector

Info

Publication number: TW201338238A
Application number: TW102107203A
Authority: TW
Inventors: Akitoshi Suzuki; Kensaku Shinozaki
Original assignee: Furukawa Electric Co Ltd
Priority date: 2012-02-28
Filing date: 2013-03-01
Publication date: 2013-09-16
Also published as: WO2013129588A1; JPWO2013129588A1; JP5598884B2

Abstract

Provided are: an electrolytic copper foil, which has similar surface configurations on both surfaces, good wettability with an active material slurry and high battery capacity, while being suppressed in deterioration of the battery capacity even if charge and discharge cycles are repeated, and wherein the active material coating film layer is not easily separated from the copper foil that serves as the negative electrode collector; and a lithium secondary battery which uses the electrolytic copper foil as a collector. An electrolytic copper foil for negative electrode collectors of lithium ion secondary batteries, wherein the both surfaces of the electrolytic copper foil are electrolytically deposited surfaces and the electrolytically deposited surfaces are composed of a columnar crystal structure. A negative electrode for lithium secondary batteries, which uses the electrolytic copper foil as a collector. A lithium secondary battery in which the negative electrode is incorporated. A first surface of the electrolytic copper foil is a surface that is formed on a drum surface by electrolytic deposition of copper of a columnar crystal structure, and a second surface that is on the reverse side of the first surface is a surface that is formed on the back side of the first surface by electrolytic deposition of copper of a columnar crystal structure after the foil formation of the first surface.

Description

鋰離子二次電池、構成該二次電池之負極電極之集電體以及構成該負極電極集電體之電解銅箔 a lithium ion secondary battery, a current collector constituting a negative electrode of the secondary battery, and an electrolytic copper foil constituting the negative electrode current collector

本發明係關於一種包括在負極集電體之表面上形成有負極活性物質層之負極、正極以及非水電解液之鋰離子二次電池、構成該二次電池之負極電極、以及構成該負極電極之集電體。 The present invention relates to a lithium ion secondary battery including a negative electrode having a negative electrode active material layer formed on a surface of a negative electrode current collector, a positive electrode and a nonaqueous electrolyte, a negative electrode constituting the secondary battery, and a negative electrode constituting the negative electrode The collector.

目前，包括正極、負極以及非水電解液之鋰離子二次電池被使用於行動電話、筆記型電腦等中，其中，負極係在由兩面平滑之電解銅箔構成的負極集電體表面上塗敷碳粒子作為負極活性物質層並乾燥，進而進行壓製而形成者。該鋰離子二次電池之負極集電體使用有對藉由電解製造之所謂「未處理銅箔」實施了表面處理之電解銅箔，其中，該表面處理用於提高防銹能力及電解銅箔與負極活性物質之黏合性。 At present, a lithium ion secondary battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is used in a mobile phone, a notebook computer, or the like, wherein the negative electrode is coated on the surface of a negative electrode current collector composed of two sides of smooth copper foil. The carbon particles are formed as a negative electrode active material layer, dried, and further pressed. The negative electrode current collector of the lithium ion secondary battery uses an electrolytic copper foil surface-treated with a so-called "untreated copper foil" manufactured by electrolysis, wherein the surface treatment is used for improving rust prevention ability and electrolytic copper foil. Adhesion to the negative active material.

作為所述鋰離子二次電池用負極集電體之銅箔，藉由使用下述電解銅箔，能夠抑制電池之充放電效率之降低，其中，上述電解銅箔係如專利文獻1所公開般將粗糙面平滑化，從而縮小光澤面與粗糙面(銅箔之兩面)之表面粗糙度之差的電解銅箔。即，在利用電解法製造電解銅箔時，一般情況下銅箔之一面為光澤面，另一面為無光澤面。通常將該另一面稱為「粗糙面」。作為所述鋰離子二次電池用負極集電體之銅箔，藉由使用下述電解銅箔，能夠抑制電池之充放電效率之降低，其中，上述電解銅箔係如專利文獻1所公開般將另一面(粗糙面)平滑化，從而縮小了光澤面與另一面(粗糙面)之兩面的表面粗糙度之差的電解銅箔。 In the copper foil of the negative electrode current collector for a lithium ion secondary battery, it is possible to suppress a decrease in the charge and discharge efficiency of the battery by using the electrolytic copper foil described below, as disclosed in Patent Document 1. The electrolytic copper foil which smoothes the rough surface to reduce the difference in surface roughness between the shiny surface and the rough surface (both sides of the copper foil). That is, when an electrolytic copper foil is produced by an electrolytic method, generally, one surface of the copper foil is a glossy surface, and the other surface is a matte surface. Usually the other side It is called "rough surface". In the copper foil of the negative electrode current collector for a lithium ion secondary battery, it is possible to suppress a decrease in the charge and discharge efficiency of the battery by using the electrolytic copper foil described below, as disclosed in Patent Document 1. The other surface (rough surface) is smoothed to reduce the difference in surface roughness between the glossy surface and the other surface (rough surface).

如上所述，另一名(粗糙面)亦平滑且其與光澤面之表面粗糙度之差得以縮小的電解銅箔可藉由以下方法進行製造，即，使用在硫酸銅-硫酸電解液中適當地選擇添加了各種水溶性高分子物質、各種表面活性劑、各種有機硫類化合物、氯化物離子等之電解液，在旋轉的鈦輥陰極上電沉積銅，當該銅達到規定厚度後將其剝下來並捲繞。 As described above, the electrolytic copper foil in which another (rough surface) is also smooth and whose difference from the surface roughness of the glossy surface is reduced can be produced by the following method, that is, using it in a copper sulfate-sulfuric acid electrolyte. An electrolyte containing various water-soluble polymer materials, various surfactants, various organic sulfur compounds, chloride ions, etc. is added, and copper is electrodeposited on the rotating titanium roll cathode, and when the copper reaches a predetermined thickness, Peel off and wrap it up.

例如，提出了在硫酸銅-硫酸電解液中添加具有巰基之化合物、氯化物離子、分子量在10,000以下之低分子量膠以及高分子多糖類來製造電解銅箔之技術(參照專利文獻1)。 For example, a technique of producing an electrolytic copper foil by adding a compound having a mercapto group, a chloride ion, a low molecular weight gel having a molecular weight of 10,000 or less, and a polymer polysaccharide to a copper sulfate-sulfuric acid electrolyte has been proposed (see Patent Document 1).

該電解銅箔之抗拉強度為300~350 N/mm²，在用作所述活性物質為碳粒子之負極用集電體(銅箔)時，因為還具有適度之延展率，因此其係合適之材料。 The electrolytic copper foil has a tensile strength of 300 to 350 N/mm ² , and when used as a current collector (copper foil) for the negative electrode in which the active material is carbon particles, since it has a moderate elongation rate, it is Suitable materials.

進而，提出了使用添加有與專利文獻1不同之有機添加劑之硫酸銅-硫酸電解液製成且平滑面的另一面(粗糙面)之粗糙度變小之電解銅箔，在目前成主流的使用碳類活性物質之鋰離子二次電池中，主要使用該種兩面平滑且兩面之表面粗糙度之差較小的電解銅箔(參照專利文獻2、專利文獻3)。 Further, an electrolytic copper foil which is made of a copper sulfate-sulfuric acid electrolyte to which an organic additive different from the patent document 1 is added and which has a smooth surface and has a small roughness (rough surface) has been proposed, and is currently in the mainstream. In the lithium ion secondary battery of the carbon-based active material, an electrolytic copper foil having a smooth surface on both sides and a small difference in surface roughness between the two surfaces is mainly used (see Patent Document 2 and Patent Document 3).

然而，近年來，提出了下述鋰離子二次電池，即，為了實現鋰離子二次電池之高容量化，負極活性物質使用在充電時會與鋰電化學合金化之合金類活性物質，例如鋁、矽、錫等(參照專利文獻4)。 However, in recent years, the following lithium ion secondary batteries have been proposed, that is, In order to increase the capacity of the lithium ion secondary battery, an alloy active material which is electrochemically alloyed with lithium during charging, such as aluminum, tantalum, tin, or the like, is used as the negative electrode active material (see Patent Document 4).

旨在實現高容量化之鋰離子二次電池用負極，係藉由利用CVD法或濺射法在銅箔等集電體上以非晶質矽薄膜或微晶矽薄膜之形式堆積例如矽而形成者。吾等發現利用該方法製成之活性物質薄膜層與集電體緊密黏合，因此充放電循環特性良好(參照專利文獻5)。 The negative electrode for a lithium ion secondary battery, which is intended to increase the capacity, is deposited in the form of an amorphous tantalum film or a microcrystalline tantalum film on a current collector such as a copper foil by a CVD method or a sputtering method. Former. We have found that the active material thin film layer produced by this method is in close contact with the current collector, and therefore has good charge and discharge cycle characteristics (see Patent Document 5).

另外，最近還開發出了下述形成方法，即，利用有機溶劑將粉末矽或矽化合物與醯亞胺類黏合劑一同形成為漿料狀後塗敷在銅箔上，並在乾燥後進行壓製。(參照專利文獻6) Further, recently, a formation method has been developed in which a powder of ruthenium or osmium compound is formed into a slurry together with an oxime imide-based adhesive by an organic solvent, and then coated on a copper foil, and dried after drying. . (Refer to Patent Document 6)

在負極活性物質之種類為碳類或合金類中之任一種時，皆要求銅箔具有下述特性，即，電池容量高，即使重複進行充放電循環，電池容量之劣化亦較少，並且活性物質薄膜層不易從作為負極集電體之銅箔上剝離。 When the type of the negative electrode active material is either carbon or alloy, the copper foil is required to have a characteristic that the battery capacity is high, and even if the charge and discharge cycle is repeated, the battery capacity is less deteriorated and active. The material thin film layer is not easily peeled off from the copper foil as the negative electrode current collector.

【現有技術文獻】 [Prior Art Literature] 【專利文獻】 [Patent Literature]

【專利文獻1】日本專利第3742144號公報 [Patent Document 1] Japanese Patent No. 3742144

【專利文獻2】日本專利特開2004-263289號公報 [Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-263289

【專利文獻3】日本專利特開2004-162144號公報 [Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-162144

【專利文獻4】日本專利特開平10-255768號公報 [Patent Document 4] Japanese Patent Laid-Open No. Hei 10-255768

【專利文獻5】日本專利特開2002-083594號公報 [Patent Document 5] Japanese Patent Laid-Open Publication No. 2002-083594

【專利文獻6】日本專利特開2007-227328號公報 [Patent Document 6] Japanese Patent Laid-Open Publication No. 2007-227328

【專利文獻7】日本專利特公昭53-39376號公報 [Patent Document 7] Japanese Patent Publication No. Sho 53-39376

【非專利文獻】 [Non-patent literature]

【非專利文獻1】：田村宣之、藤本洋行、大下龍司、藤本正久、神野丸男：「鋰離子二次電池用高容量錫負極材料之電化學特性」三洋電機技報，Vol.34，Nol，JUN.p87~p93(2002) [Non-Patent Document 1]: Tamura Hiroshi, Fujimoto Yosuke, Otoshi Ryusuke, Fujimoto Masahiro, and Shinno Maru: "Electrochemical Characteristics of High Capacity Tin Anode Materials for Lithium Ion Secondary Batteries" Sanyo Electric Technology Report, Vol.34, Nol , JUN.p87~p93 (2002)

本發明之課題在於：提供一種活性物質漿料之潤濕性良好、電池容量高、即使重複進行充放電循環，電池容量之劣化亦較小、活性物質塗膜層不易從作為負極集電體之銅箔上剝離且兩面形狀程度相同之電解銅箔，並提供以該電解銅箔為集電體，在該集電體上堆積活性物質而形成負極電極，並組裝該負極電極之鋰離子二次電池。 An object of the present invention is to provide a slurry of an active material which has good wettability and a high battery capacity. Even if the charge and discharge cycle is repeated, the battery capacity is less deteriorated, and the active material coating layer is less likely to be used as a negative electrode collector. An electrolytic copper foil having a double-sided shape and having the same shape on both sides of the copper foil is provided, and the electrolytic copper foil is used as a current collector, and an active material is deposited on the current collector to form a negative electrode, and the lithium ion of the negative electrode is assembled twice. battery.

本發明之鋰離子二次電池係包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液之鋰離子二次電池，其中，構成該鋰離子二次電池之負極之所述集電體由電解銅箔構成，該電解銅箔之兩面藉由電沉積形成，該電沉積面為柱狀晶之結晶組織。 The lithium ion secondary battery of the present invention includes a positive electrode, a negative electrode having an electrode formed on the surface of the current collector to form an active material layer, and a nonaqueous electrolyte lithium ion secondary battery, wherein the lithium ion secondary battery is configured The current collector of the negative electrode is composed of an electrolytic copper foil, and both sides of the electrolytic copper foil are formed by electrodeposition, and the electrodeposited surface is a crystal structure of columnar crystals.

本發明之鋰離子二次電池用集電體係構成鋰離子二次電池之所述負極之集電體，該鋰離子二次電池包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液，其中，該集電體由電解銅箔構成，該電解銅箔之兩面藉由電沉積形成，該電沉積面為柱狀晶之結晶組織。 The current collecting system for a lithium ion secondary battery of the present invention constitutes a current collector of the negative electrode of a lithium ion secondary battery, and the lithium ion secondary battery includes a positive electrode, and an electrode is formed on the surface of the current collector to constitute an active material layer. And a non-aqueous electrolyte, wherein the current collector is made of an electrolytic copper foil, and both sides of the electrolytic copper foil are formed by electrodeposition, and the electrodeposited surface is a crystal structure of columnar crystals.

本發明之鋰離子二次電池負極集電體用電解銅箔係構成包括正極、負極以及非水電解液之鋰離子二次電池之所述負極集電體之電解銅箔，其中，該電解銅箔之兩面藉由電沉積形成，該電沉積面為柱狀晶之結晶組織。 The electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery of the present invention comprises an electrolytic copper foil of the negative electrode current collector including a positive electrode, a negative electrode, and a lithium ion secondary battery of a nonaqueous electrolyte, wherein the electrolytic copper foil Both sides of the foil are formed by electrodeposition, which is a crystal structure of columnar crystals.

本發明之鋰離子二次電池係包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液之鋰離子二次電池，其中，構成所述負極之所述集電體係電沉積銅而形成之電解銅箔，該電解銅箔之第一表面係在輥面上電沉積結晶組織為柱狀晶之銅而形成的面，該第一表面之相反側之第二表面係在製成第一表面後，在第一表面之背側電沉積結晶組織為柱狀晶之銅而形成的面。 The lithium ion secondary battery of the present invention includes a positive electrode, a negative electrode having an electrode formed on the surface of the current collector to form an active material layer, and a nonaqueous electrolyte lithium ion secondary battery, wherein the negative electrode is formed An electrolytic copper foil formed by electrodepositing copper by a current collecting system, wherein a first surface of the electrolytic copper foil is a surface formed by electrodepositing a crystal structure into a columnar crystal copper on a surface of the roller, and a surface opposite to the first surface After the surface is formed into the first surface, the surface formed by depositing the crystal structure into the copper of the columnar crystal is electrodeposited on the back side of the first surface.

本發明之鋰離子二次電池用負極集電體係構成包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液之鋰離子二次電池的負極集電體，其中，該負極集電體係電沉積銅而形成的電解銅箔，該電解銅箔之第一表面係在輥面上電沉積結晶組織為柱狀晶之銅而形成的面，該第一表面之相反側之第二表面係在製成第一表面後，在第一表面之背側電沉積結晶組織為柱狀晶之銅而形成的面。 The negative electrode current collecting system for a lithium ion secondary battery of the present invention comprises a negative electrode current collector including a positive electrode, a negative electrode on which an electrode is formed on the surface of the current collector, and a negative electrode current collector of a nonaqueous electrolyte lithium ion secondary battery. The electrolytic copper foil formed by electrodepositing copper in the negative electrode current collecting system, wherein the first surface of the electrolytic copper foil is a surface formed by electrodepositing a crystal structure into a columnar crystal copper on a surface of the roller, the first surface The second surface on the opposite side is a surface formed by depositing a crystal structure into a columnar crystal copper on the back side of the first surface after the first surface is formed.

本發明之鋰離子二次電池負極集電體用電解銅箔係構成包括正極、負極以及非水電解液之鋰離子二次電池之負極集電體用電解銅箔，其中，該電解銅箔係電沉積銅而形成者，該電解銅箔之第一表面係在輥面上電沉積結晶組織為柱狀晶之銅而形成的面，該第一表面之相反側之第二表面係在製成第一表面後，在第一表面之背側電沉積結晶組織為柱狀晶之銅而形成的面。 The electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery of the present invention comprises an electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte, wherein the electrolytic copper foil is Forming the electrodeposited copper, the first surface of the electrolytic copper foil is a surface formed by electrodepositing a crystal structure into a columnar crystal copper on a surface of the roller, and a second surface of the opposite side of the first surface is formed After the first surface, the crystal structure is electrodeposited on the back side of the first surface to be a columnar crystal copper And the face formed.

本發明之銅箔能夠提供活性物質漿料之塗敷性出色、且活性物質塗膜層不易剝離之電解銅箔。另外，亦能夠將兩面形成為程度相同之柱狀晶組織。 The copper foil of the present invention can provide an electrolytic copper foil having excellent coating properties of the active material slurry and in which the active material coating film layer is not easily peeled off. Further, it is also possible to form both surfaces into a columnar crystal structure of the same degree.

另外，本發明藉由以所述電解銅箔為集電體，在該集電體上堆積活性物質從而形成負極電極，並形成組裝有該負極電極之鋰離子二次電池，從而能夠提供活性物質堆積層不易從作為負極集電體之銅箔上剝離之集電體，實現即使重複進行充放電循環，電池容量之劣化亦較小且耐久性出色之鋰離子電池。另外，亦能夠提供電池容量高之鋰離子二次電池。 Further, in the present invention, the electrolytic copper foil is used as a current collector, and an active material is deposited on the current collector to form a negative electrode, and a lithium ion secondary battery in which the negative electrode is assembled is formed, thereby providing an active material. The current collector in which the build-up layer is not easily peeled off from the copper foil as the negative electrode current collector realizes a lithium ion battery which is less deteriorated in battery capacity and excellent in durability even when the charge and discharge cycle is repeated. In addition, it is also possible to provide a lithium ion secondary battery having a high battery capacity.

1‧‧‧電解銅箔 1‧‧‧electrolytic copper foil

2‧‧‧兩面為沉積面之電解銅箔 2‧‧‧ Electrolytic copper foil with deposition surface on both sides

11‧‧‧輥 11‧‧‧ Roll

12‧‧‧輥 12‧‧‧ Roll

101‧‧‧輥面 101‧‧‧ Roll surface

102‧‧‧電沉積面 102‧‧‧Electrodeposited surface

103‧‧‧電沉積面 103‧‧‧Electrolytic surface

圖1係顯示製造兩面形狀相同之電解銅箔之工序的一實施例之說明圖。 Fig. 1 is an explanatory view showing an embodiment of a process for producing an electrolytic copper foil having the same shape on both sides.

圖2係現有的製造電解銅箔之裝置之說明圖。 Fig. 2 is an explanatory view of a conventional apparatus for manufacturing an electrolytic copper foil.

圖3顯示本發明之電解銅箔的第一實施例，A：係顯示最初形成的電沉積面(粗糙面)之掃描電子顯微鏡照片(SEM)，B：係顯示接著形成的電沉積面之掃描電子顯微鏡照片(SEM)。 Figure 3 shows a first embodiment of the electrodeposited copper foil of the present invention, A: shows a scanning electron micrograph (SEM) of the initially formed electrodeposited surface (rough surface), and B: shows a scan of the subsequently formed electrodeposited surface Electron micrograph (SEM).

圖4顯示本發明之電解銅箔的第二實施例，A：係顯示最初形成的電沉積面(粗糙面)之掃描電子顯微鏡照片(SEM)，B：係顯示接著形成的電沉積面之掃描電子顯微鏡照片(SEM)。 Fig. 4 shows a second embodiment of the electrolytic copper foil of the present invention, A: showing a scanning electron micrograph (SEM) of the initially formed electrodeposited surface (rough surface), and B: showing scanning of the subsequently formed electrodeposited surface Electron micrograph (SEM).

圖5顯示本發明之電解銅箔的第三實施例，A：係顯示最初形成的電沉積面(粗糙面)之掃描電子顯微鏡照片(SEM)，B：係顯示接著形成的電沉積面之掃描電子顯微鏡照片(SEM)。 Figure 5 shows a third embodiment of the electrolytic copper foil of the present invention, A: shows the most Scanning electron micrograph (SEM) of the initially formed electrodeposited surface (rough surface), B: shows a scanning electron micrograph (SEM) of the electrodeposited surface formed next.

圖6係現有電解銅箔(比較例1)之掃描電子顯微鏡照片(SEM)，X：顯示電沉積面(粗糙面)，Y：顯示光澤面。 Fig. 6 is a scanning electron micrograph (SEM) of a conventional electrolytic copper foil (Comparative Example 1), X: shows an electrodeposited surface (rough surface), and Y: shows a glossy surface.

圖7係現有電解銅箔(比較例2)之掃描電子顯微鏡照片(SEM)，X：顯示電沉積面(粗糙面)，Y：顯示光澤面。 Fig. 7 is a scanning electron micrograph (SEM) of a conventional electrolytic copper foil (Comparative Example 2), X: shows an electrodeposited surface (rough surface), and Y: shows a glossy surface.

圖8係現有的光澤面之另一面(粗糙面)平滑的電解銅箔(比較例3)之掃描電子顯微鏡照片(SEM)，X：顯示電沉積面(粗糙面)，Y：顯示光澤面。 Fig. 8 is a scanning electron micrograph (SEM) of an electrolytic copper foil (Comparative Example 3) on the other side (rough surface) of the conventional glossy surface, X: shows an electrodeposited surface (rough surface), and Y: shows a glossy surface.

圖9係對所述圖8之電解銅箔(比較例3)表面實施了燒鍍處理後的表面之掃描電子顯微鏡照片(SEM)，X：顯示在電沉積面(粗糙面)上實施了燒鍍處理後的面，Y：顯示在光澤面上實施了燒鍍處理後的面。 Fig. 9 is a scanning electron micrograph (SEM) of the surface on which the surface of the electrodeposited copper foil (Comparative Example 3) of Fig. 8 was subjected to a baking treatment, and X: shows that the surface of the electrodeposited surface (rough surface) was burned. The surface after the plating treatment, Y: shows the surface on which the polished surface was subjected to the baking treatment.

圖10係本發明電解銅箔的剖面的結晶組織之示意圖。 Fig. 10 is a schematic view showing the crystal structure of a cross section of the electrodeposited copper foil of the present invention.

圖11係說明組裝於電池中的負極活性物質之狀態之示意圖。 Fig. 11 is a view showing the state of the negative electrode active material assembled in the battery.

在本說明書中，將電解銅箔之與電解液接觸之面稱為「電沉積面」或者「粗糙面」。即，本發明之電解銅箔的一面為電沉積面，另一面亦為與電沉積面相同之柱狀晶組織。 In the present specification, the surface of the electrolytic copper foil that is in contact with the electrolytic solution is referred to as "electrodeposited surface" or "rough surface". That is, one side of the electrodeposited copper foil of the present invention is an electrodeposited surface, and the other side is also a columnar crystal structure identical to the electrodeposited surface.

兩面均為電沉積面之電解銅箔之兩面均由與電解液接觸之面構成，從而能夠利用例如下述圖1所示之製箔裝置進行製造。 Both surfaces of the electrodeposited copper foil having the electrodeposited surfaces on both sides are formed by a surface in contact with the electrolytic solution, and can be manufactured by, for example, a foil forming apparatus shown in Fig. 1 described below.

電解銅箔一般如下進行製造，即，如圖2所示，配置旋轉的鈦輥21並在其下側配置不溶性陽極22(以下稱之為“DSA”)，在鈦輥21與DSA22之間流入硫酸銅-硫酸電解液23，並且以鈦輥21為陰極、以DSA22為陽極在鈦輥-DSA之間接通電流，由此來製造銅箔24。 The electrolytic copper foil is generally manufactured as follows, that is, as shown in Fig. 2, a rotating titanium roll 21 is disposed and an insoluble anode 22 (hereinafter referred to as "DSA") is disposed on the lower side thereof, and flows between the titanium roll 21 and the DSA 22 The copper sulfate-sulfuric acid electrolyte 23 is used, and the copper foil 24 is manufactured by turning on a current between the titanium roller and the DSA with the titanium roller 21 as a cathode and the DSA 22 as an anode.

當在鈦輥21與DSA22之間接通電流時，銅會電沉積於鈦輥21上。當該銅達到規定厚度時，將該銅連續地剝下來並捲繞，由此製成電解銅箔24。通常，將該狀態下的銅箔稱為「未處理銅箔」。 When a current is applied between the titanium roller 21 and the DSA 22, copper is electrodeposited on the titanium roller 21. When the copper reaches a predetermined thickness, the copper is continuously peeled off and wound, thereby producing an electrolytic copper foil 24. Usually, the copper foil in this state is called "untreated copper foil".

利用圖2所示之製造方法製成的電解銅箔24，通常將與電解液23接觸之面241稱為「粗糙面」，將與鈦輥21接觸之面242稱為「光澤面」，如下述圖6、圖7所示，與電解液23接觸之面241和與鈦輥21接觸之面242之表面形狀不同。 The electrodeposited copper foil 24 produced by the manufacturing method shown in Fig. 2 is generally referred to as a "rough surface" in contact with the electrolyte 23, and a surface 242 in contact with the titanium roller 21 is referred to as a "glossy surface" as follows. 6 and 7, the surface shape of the surface 241 which is in contact with the electrolytic solution 23 and the surface 242 which is in contact with the titanium roller 21 are different.

與鈦輥接觸之「光澤面」在目視時具有光澤，乍看似乎為平滑面，但是，當利用SEM觀察時，如圖6(比較例1)Y：光澤面所示，銅箔之MD方向(縱向)上具有條紋狀凹凸。 The "glossy surface" in contact with the titanium roller has a luster when visually observed, and appears to be a smooth surface at first glance. However, when observed by SEM, as shown in Fig. 6 (Comparative Example 1) Y: shiny side, the MD direction of the copper foil Stripe-like irregularities (in the longitudinal direction).

相對於此，圖6(比較例1)X：電沉積面(粗糙面)上未看到如光澤面般之條紋狀凹凸，並且，在電解銅箔之結晶組織為柱狀晶時，電沉積面(粗糙面)上具有不同於「光澤面」之金字塔狀凹凸。 On the other hand, in FIG. 6 (Comparative Example 1) X: no streaky unevenness such as a glossy surface was observed on the electrodeposited surface (rough surface), and electrodeposition was performed when the crystal structure of the electrolytic copper foil was columnar crystal. The surface (rough surface) has pyramidal irregularities different from the "glossy surface".

「光澤面」在銅箔之MD方向(縱向)上具有條紋狀凹凸的原因在於：「光澤面」係與鈦輥接觸之面。鈦輥係在將表面研磨後配置在圖2所示之電解槽26中從而製造銅箔(製箔)者。 The reason why the "glossy surface" has streak-like irregularities in the MD direction (longitudinal direction) of the copper foil is that the "glossy surface" is the surface in contact with the titanium roller. Titanium roller system After the surface is ground, it is placed in the electrolytic cell 26 shown in Fig. 2 to manufacture a copper foil (foil).

此時，因為所使用之硫酸銅-硫酸電解液之溫度為50℃左右的較高溫度，因此，在持續製造之過程中，鈦輥21的表面逐漸變粗糙，從而導致銅箔24不易剝離。為了避免發生上述狀況，在製造了一定時間的銅箔後，要定期地對鈦輥表面進行研磨，然後再繼續進行製造。 At this time, since the temperature of the copper sulfate-sulfuric acid electrolyte used is a relatively high temperature of about 50 ° C, the surface of the titanium roll 21 is gradually roughened during the continuous manufacturing, and the copper foil 24 is not easily peeled off. In order to avoid the above situation, after the copper foil is produced for a certain period of time, the surface of the titanium roll is periodically polished, and then the manufacturing is continued.

通常利用圓筒形研磨布來研磨鈦輥表面，該研磨布係在尼龍不織布等上均勻地黏附浸滲有氧化鋁、碳化矽等磨料者。 The surface of the titanium roll is usually ground by a cylindrical polishing cloth which is uniformly adhered to an abrasive impregnated with alumina or tantalum carbide on a nylon nonwoven fabric or the like.

製成的銅箔之「光澤面」上複製有利用上述研磨布等對表面進行了研磨的鈦輥上的「研磨條紋」。 On the "glossy surface" of the produced copper foil, "grinding stripe" on a titanium roll polished on the surface by the above-mentioned polishing cloth or the like is reproduced.

因此，在通常之製造方法中，無法避免在「光澤面」之MD方向(縱向)上存在圖6(比較例1)Y：「光澤面」所示之條紋狀凹凸。 Therefore, in the usual manufacturing method, it is unavoidable that the stripe-shaped unevenness shown in FIG. 6 (Comparative Example 1) Y: "glossy surface" exists in the MD direction (longitudinal direction) of the "glossy surface".

圖6和圖7所示銅箔目前被用作印刷配線板用銅箔。印刷配線板用銅箔使用下述銅箔，即，在該銅箔之「電沉積面(粗糙面)」上附著銅粒子從而進一步進行粗化處理後，實施各種電鍍處理、防銹處理等的銅箔。 The copper foil shown in Figs. 6 and 7 is currently used as a copper foil for printed wiring boards. In the copper foil for a printed wiring board, copper foil is adhered to the "electrodeposited surface (rough surface)" of the copper foil, and further roughening treatment is performed, and various plating treatments, rustproof treatment, and the like are performed. Copper foil.

但是，迄今為止，這種銅箔還未被用作鋰離子二次電池之負極集電體。 However, to date, such a copper foil has not been used as a negative electrode collector of a lithium ion secondary battery.

其理由為：在使用碳類活性物質之鋰離子二次電池中，「光澤面」與「電沉積面(粗糙面)」的充放電效率不同。已知表面形狀凹凸不平之「電沉積面(粗糙面)」的充放電效率遠遜於平滑之「光澤面」(參照專利文獻1)。 The reason for this is that in a lithium ion secondary battery using a carbon-based active material, the "glossy surface" and the "electrodeposited surface (rough surface)" are different in charge and discharge efficiency. It is known that the surface of the surface is uneven and the "electrodeposited surface (rough surface)" is charged and discharged. The electrical efficiency is far less than the smooth "glossy surface" (see Patent Document 1).

相對於此，在為了實現鋰離子二次電池之高容量化，鋰離子二次電池的負極活性物質使用在充電時會與鋰電化學合金化之合金類活性物質、例如鋁、矽、錫等時，已確認與平滑的壓延銅箔相比，具有凹凸的電解銅箔之充放電效率良好(參照非專利文獻1)。 On the other hand, in order to increase the capacity of the lithium ion secondary battery, the negative electrode active material of the lithium ion secondary battery uses an alloy active material that is electrochemically alloyed with lithium during charging, such as aluminum, bismuth, tin, or the like. In addition, it is confirmed that the electrolytic copper foil having irregularities has a good charge and discharge efficiency as compared with the smooth rolled copper foil (see Non-Patent Document 1).

目前，藉由在集電體之表面上形成凹凸，一般認為具有如下效果，即，減小隨著充放電循環而產生之活性物質之膨脹收縮對集電體(銅箔)的影響，防止在作為集電體之銅箔上產生折皺等，並防止銅箔發生斷裂。 At present, by forming irregularities on the surface of the current collector, it is generally considered to have an effect of reducing the influence of expansion and contraction of the active material generated by the charge and discharge cycle on the current collector (copper foil) and preventing Wrinkles and the like are generated on the copper foil as the current collector, and the copper foil is prevented from being broken.

即，如圖11所示，當在表面具有凹凸之粗化電解銅箔(集電體)上形成活性物質層時，活性物質進入形成於集電體表面之凹凸中形成活性物質層〔圖11(A)〕。當初次對以形成有該活性物質層之集電體為負極電極之鋰離子二次電池充電時，活性物質會存儲鋰離子，由此使活性物質之體積膨脹，從而使活性物質層變得緊密〔圖11(B)〕。接著，藉由第一次放電而將鋰離子釋放出來，從而使活性物質收縮，由此沿著粗化電解銅箔之「粗面之凹部」產生龜裂，從而「沿著凸部」分離成島狀〔圖11(C)〕。 That is, as shown in Fig. 11, when the active material layer is formed on the roughened electrolytic copper foil (current collector) having irregularities on the surface, the active material enters the unevenness formed on the surface of the current collector to form an active material layer (Fig. 11). (A)]. When the lithium ion secondary battery in which the current collector formed with the active material layer is the negative electrode is charged for the first time, the active material stores lithium ions, thereby expanding the volume of the active material, thereby making the active material layer compact. [Fig. 11 (B)]. Then, by releasing the lithium ions by the first discharge, the active material is shrunk, thereby causing cracks along the "recessed portion of the rough surface" of the roughened electrolytic copper foil, thereby separating the islands along the convex portion. Shape [Fig. 11 (C)].

藉由下一次充電使活性物質再次膨脹，從而使龜裂變窄〔圖11(D)〕。但是，一般認為即使之後重複進行充放電，龜裂部份仍可減緩膨脹收縮，從而維持島狀部份，緩和集電體整體之變形，由此具有防止在作為集電體之銅箔上產生折皺等，並防止銅箔發生斷裂之效果。 The active material is expanded again by the next charge to narrow the crack (Fig. 11(D)). However, it is generally considered that even if the charge and discharge are repeated afterwards, the crack portion can slow down the expansion and contraction, thereby maintaining the island portion, and alleviating the deformation of the current collector as a whole, thereby preventing generation on the copper foil as the current collector. Wrinkles, etc., and prevent the copper foil from breaking.

因此，認為只要能夠與具有凹凸之「電沉積面(粗糙面)」同樣地在平滑的「光澤面」上形成凹凸，即能夠得到兩面皆具有高充放電效率之負極集電體。 Therefore, it is considered that a negative electrode current collector having high charge and discharge efficiency on both sides can be obtained by forming irregularities on a smooth "glossy surface" similarly to the "electrodeposited surface (rough surface)" having irregularities.

本發明人等為了使「光澤面」和「電沉積面(粗糙面)」之表面形狀一致而對下述情況進行了研究，即，使用與製造電解銅箔時相同之電解液在製成的銅箔之「光澤面」上實施鍍銅，從而在「光澤面」上形成凹凸，由此將「光澤面」亦形成為與「電沉積面(粗糙面)」相同之形狀，從而製成鋰離子二次電池用負極集電體。 The present inventors have studied the following cases in order to match the surface shapes of the "glossy surface" and the "electrodeposited surface (rough surface)", that is, the same electrolytic solution as that used in the production of the electrolytic copper foil. Copper plating is applied to the "glossy surface" of the copper foil to form irregularities on the "glossy surface", whereby the "glossy surface" is formed into the same shape as the "electrodeposited surface (rough surface)" to form lithium. A negative electrode current collector for an ion secondary battery.

另外，在另一實施方式中，認為只要能夠得到與「電沉積面(粗糙面)」相同之形狀，即能夠有效地使用組成與製造電解銅箔時不同之電解液在「光澤面」上形成凹凸，並對此認真仔細地進行了研究。 In addition, in another embodiment, it is considered that an electrolyte having a composition different from that of the "electrodeposited surface (rough surface)" can be used effectively on the "gloss surface" when the composition is different from that of the electrolytic copper foil. Bump, and carefully studied this.

鋰離子二次電池負極集電體用電解銅箔、尤其是作為堆積有膨脹和收縮劇烈之活性物質之集電體之電解銅箔表面優選為具有凹凸的面。藉由將銅之結晶組織形成為柱狀晶，能夠有效地在此種鋰離子二次電池用集電體之表面上形成凹凸。 The surface of the electrodeposited copper foil for a negative electrode current collector of a lithium ion secondary battery, in particular, the surface of the electrodeposited copper foil which is a current collector in which an active material which is swollen and contracted is highly concentrated is preferably a surface having irregularities. By forming the crystal structure of copper into columnar crystals, it is possible to effectively form irregularities on the surface of such a current collector for a lithium ion secondary battery.

藉由適當地選擇添加於銅電解液中之添加劑，能夠形成為在銅箔表面上具有凹凸之電沉積面，即形成為柱狀晶(參照實施例)。 By appropriately selecting the additive to be added to the copper electrolytic solution, it is possible to form an electrodeposited surface having irregularities on the surface of the copper foil, that is, to form columnar crystals (see the examples).

在利用呈柱狀晶之銅電解液進行電沉積時，電沉積表面會成為具有凹凸之表面。相對於此，在選擇呈粒狀晶之銅電解液進行電沉積時，電沉積表面不會成為具有凹凸之表面，而是平滑且具有光澤之表面。因此，為了得到兩面均具有凹凸之銅箔，可使用可電沉積柱狀晶之銅電解液。 When electrodeposition is performed using a copper electrolyte having a columnar crystal, the electrodeposited surface becomes a surface having irregularities. On the other hand, when electrodepositing a copper electrolytic solution in the form of granular crystals is selected, the electrodeposited surface does not become a surface having irregularities. A smooth, shiny surface. Therefore, in order to obtain a copper foil having irregularities on both sides, a copper electrolytic solution capable of electrodepositing columnar crystals can be used.

在集電體採用銅箔時，藉由以柱狀晶形成集電體表面(增大表面凹凸)，可如圖11所示，對應膨脹和收縮劇烈之活性物質，發揮出色的性能。另一方面，相對於膨脹和收縮小之活性物質(例如碳類)，可以利用粒狀晶之表面進行對應。 When the current collector is made of a copper foil, by forming the surface of the current collector in columnar crystals (increasing the surface unevenness), as shown in FIG. 11, the active material which is vigorously expanded and contracted can exhibit excellent performance. On the other hand, the active material (for example, carbon) having a small expansion and contraction can be made to correspond to the surface of the granular crystal.

本發明之鋰離子二次電池負極集電體用電解銅箔係在「未處理銅箔」之狀態下將其兩面加工成具有柱狀晶組織之凹凸面。即，將銅箔製造工序分為兩個階段，首先，在第一階段中，將「電沉積面(粗糙面)(第一表面)」加工成具有柱狀晶組織之凹凸面，在第二階段中，將第一階段中之「光澤面(第二表面)」側加工成具有柱狀晶組織之凹凸面。在第二階段中進行柱狀晶銅之電沉積，該柱狀晶銅之厚度為將第一工序中形成的「光澤面」之平滑形狀消除之厚度，從而將兩面均形成為與「電沉積面(粗糙面)」相同的由柱狀晶構成之表面形狀，由此可加工成具有凹凸之銅箔。 In the lithium ion secondary battery negative electrode current collector of the present invention, the electrolytic copper foil is processed into an uneven surface having a columnar crystal structure in the state of "untreated copper foil". That is, the copper foil manufacturing process is divided into two stages. First, in the first stage, the "electrodeposited surface (rough surface) (first surface)" is processed into an uneven surface having a columnar crystal structure, and in the second In the stage, the "glossy surface (second surface)" side in the first stage is processed into an uneven surface having a columnar crystal structure. In the second stage, electrodeposition of columnar crystal copper is performed, and the thickness of the columnar crystal copper is a thickness which eliminates the smooth shape of the "glossy surface" formed in the first step, thereby forming both sides and "electrodeposition" The surface shape of the surface (rough surface) having the same columnar crystal can be processed into a copper foil having irregularities.

圖1顯示上述電解銅箔之具體製造方法的一例。 Fig. 1 shows an example of a specific production method of the above-mentioned electrolytic copper foil.

在利用第一輥11製成結晶組織為柱狀晶之銅箔後，將該銅箔1從第一輥11上剝下來，利用第二輥12在銅箔1之光澤面101側電沉積結晶組織為柱狀晶之銅，從而將光澤面101形成為電沉積面103，由此與電沉積面(粗糙面)102一同將兩面均加工成具有凹凸之表面形狀。 After the first roll 11 is used to form a copper foil having a crystal structure of a columnar crystal, the copper foil 1 is peeled off from the first roll 11, and the second roll 12 is used to electrodeposite crystal on the shiny side 101 side of the copper foil 1. The structure is a columnar crystal copper, whereby the glossy surface 101 is formed as the electrodeposited surface 103, whereby both surfaces are processed into a surface shape having irregularities together with the electrodeposited surface (rough surface) 102.

此時，第一電解槽16與第二電解槽17中的電解液13、18為同一電解液則更便於製造，但是，即使第一電解槽16與第二電解槽17中使用液體組成不同之電解液，亦能夠使兩面之表面形狀相同。 At this time, the electrolysis in the first electrolytic cell 16 and the second electrolytic cell 17 Although the liquids 13 and 18 are the same electrolyte solution, it is easier to manufacture. However, even if the electrolyte solution having a different liquid composition is used in the first electrolytic cell 16 and the second electrolytic cell 17, the surface shapes of both surfaces can be made the same.

即使利用第一輥11電沉積結晶組織為柱狀晶之銅時，使用組成與第一電解槽16不同之銅電解液，亦可藉由利用第二輥12電沉積柱狀晶之銅，從而使兩面之形狀相同。 Even when the first roller 11 is used to electrodeposit the crystal structure into the columnar crystal copper, the copper electrolyte having a composition different from that of the first electrolytic cell 16 is used, and the columnar crystal copper can be electrodeposited by using the second roller 12, thereby Make the shape of both sides the same.

另外，採用利用第一輥形成的銅箔之厚度與利用第二輥形成的銅鍍層之厚度相同的方法，更加容易得到兩面形狀相同之銅箔。但是，也可以增大利用第一輥形成的銅箔之厚度，並減小利用第二輥形成的銅鍍層之厚度。 Further, by using the same method as the thickness of the copper plating layer formed by the second roll using the thickness of the copper foil formed by the first roll, it is easier to obtain the copper foil having the same double-sided shape. However, it is also possible to increase the thickness of the copper foil formed by the first roll and to reduce the thickness of the copper plating layer formed by the second roll.

前一種方法適於製造35 μm左右的較厚的銅箔，而後一種方法適於製造6 μm左右的較薄的銅箔。 The former method is suitable for producing a thick copper foil of about 35 μm, and the latter method is suitable for manufacturing a thin copper foil of about 6 μm.

例如，在利用第一輥製成3 μm的銅箔，利用第二輥在該銅箔之「輥面」上形成3 μm的銅鍍層時，因為利用第一輥形成的銅箔較薄而容易斷裂，因此不易進行製造。 For example, when a 3 μm copper foil is formed by the first roll and a 3 μm copper plating layer is formed on the "roller surface" of the copper foil by the second roll, since the copper foil formed by the first roll is thin and easy It breaks and is therefore difficult to manufacture.

相對於此，在後一種方法中，只要利用第一輥製成銅箔之抗拉強度足夠高，便可以例如利用第一輥製造5.0 μm的銅箔，並利用第二輥在「輥面」上形成1.0 μm的銅鍍層。 On the other hand, in the latter method, as long as the tensile strength of the copper foil formed by the first roll is sufficiently high, for example, a copper foil of 5.0 μm can be produced by the first roll, and the "roller face" can be used by the second roll. A 1.0 μm copper plating layer was formed thereon.

另外，在根據上述製造方法進行製造時，銅箔之厚度優選為6~35 μm。 Further, in the case of production according to the above production method, the thickness of the copper foil is preferably 6 to 35 μm.

如上所述，本發明之包括正極和負極的鋰離子二次電池之負極集電體，首先藉由電沉積具有柱狀晶組織之銅，從而在最初形成具有「光澤面」和「電沉積面(粗糙面)」之電解銅箔，其中，上述正極和負極係在集電體之表面上形成電極構成活性物質層而構成的。 As described above, the anode current collector of the lithium ion secondary battery including the positive electrode and the negative electrode of the present invention firstly forms a "glossy surface" and a "electrodeposition surface" by electrodepositing copper having a columnar crystal structure. (rough surface) electrolytic copper foil in which the above positive electrode and negative electrode form electricity on the surface of the current collector The pole is composed of an active material layer.

接著，藉由於下一工序中電沉積結晶組織為柱狀晶的銅，使其具有在「光澤面」上形成凹凸之厚度，從而在上述電解銅箔之「光澤面」上設置成為「電沉積面」之銅層。 Then, by depositing copper into a columnar crystal in the next step, the thickness of the uneven surface is formed on the "gloss surface", thereby providing "electrodeposition" on the "glossy surface" of the electrolytic copper foil. The copper layer of the face.

圖10係電解銅箔之剖視圖，該電解銅箔利用第一輥並以下述電解液組成和電解條件製造厚度為12 μm的電解銅箔，接著利用第二輥以相同條件在光澤面側沉積了厚度為12 μm的銅。 Fig. 10 is a cross-sectional view showing an electrolytic copper foil which is produced by using a first roll and having an electrolytic solution having a thickness of 12 μm by the following electrolyte composition and electrolytic conditions, and then deposited on the glossy side by the second roller under the same conditions. Copper with a thickness of 12 μm.

電解液組成和電解條件：Cu=50~150 g/L Electrolyte composition and electrolysis conditions: Cu=50~150 g/L

H₂SO₄=20~200 g/L H ₂ SO ₄ =20~200 g/L

氯化物離子=1~60 ppm Chloride ion = 1~60 ppm

羥乙基纖維素=1~30 ppm Hydroxyethyl cellulose = 1~30 ppm

溫度=30~70℃ Temperature = 30~70°C

電流密度：30~100 A/dm² Current density: 30~100 A/dm ²

如圖10所示，銅箔兩面為柱狀晶之結晶組織。 As shown in FIG. 10, both sides of the copper foil are crystal structures of columnar crystals.

藉由得到上述兩面形狀相同之銅箔，在塗敷活性物質漿料時，能夠得到同樣的潤濕性，從而容易設定活性物質塗敷工序之條件，並且兩面之塗膜結構相同，能夠得到相同程度之充放電特性，作為電池能夠發揮極其穩定之性能。 By obtaining the copper foil having the same double-sided shape, the same wettability can be obtained when the active material slurry is applied, and the conditions of the active material application step can be easily set, and the coating film structures on both sides can be the same, and the same can be obtained. The degree of charge and discharge characteristics, as a battery can play extremely stable performance.

將如此製成之電解銅箔作為負極集電體，在該負極集電體上堆積活性物質從而形成負極電極，將該負極電極組裝後製成鋰離子二次電池。 The electrolytic copper foil thus produced was used as a negative electrode current collector, and an active material was deposited on the negative electrode current collector to form a negative electrode, and the negative electrode was assembled to obtain a lithium ion secondary battery.

上述銅箔在製成後完全未進行任何表面處理，因此被分類為「未處理銅箔」。「未處理銅箔」係未實施任何表面處理之半成品。在將該銅箔用作電池用銅箔時，必須根據需要實施某種表面處理。 The above copper foil is not subjected to any surface treatment at all because This is classified as "untreated copper foil". "Untreated copper foil" is a semi-finished product that has not been subjected to any surface treatment. When the copper foil is used as a copper foil for a battery, it is necessary to carry out a certain surface treatment as needed.

表面處理係用於在未處理電解銅箔表面上形成凹凸之處理、以及用於提高防銹性能和銅箔與電極構成活性物質層之黏合性之處理。 The surface treatment is a treatment for forming irregularities on the surface of the untreated electrolytic copper foil, and a treatment for improving the rust prevention performance and the adhesion between the copper foil and the electrode to constitute the active material layer.

為了增大未處理電解銅箔表面上的凹凸，可根據需要進一步實施粗化處理。該粗化處理可以適當地採用電鍍法、氣相外延法、蝕刻法以及研磨法等。 In order to increase the unevenness on the surface of the untreated electrodeposited copper foil, the roughening treatment may be further carried out as needed. As the roughening treatment, an electroplating method, a vapor phase epitaxing method, an etching method, a polishing method, or the like can be suitably employed.

電鍍法和氣相外延法係藉由在未處理電解銅箔之表面上形成具有凹凸之薄膜層來使表面粗化之方法。電鍍法可採用電解電鍍法和非電解電鍍法。另外，氣相外延法可以採用濺射法、CVD法以及蒸鍍法等。 The electroplating method and the vapor phase epitaxy method are methods for roughening a surface by forming a thin film layer having irregularities on the surface of an untreated electrolytic copper foil. The electroplating method may employ electrolytic plating and electroless plating. Further, as the vapor phase epitaxy method, a sputtering method, a CVD method, a vapor deposition method, or the like can be used.

作為藉由電鍍使表面粗化之方法，優選使用例如藉由專利文獻7所公開之通常針對印刷電路用銅箔使用之電鍍進行的粗化方法。即，在利用所謂的「燒鍍」形成粉粒狀銅鍍層後，在該粉粒狀銅鍍層上以不損壞其凹凸形狀之方式實施「包鍍」，並堆積實質上平滑的鍍層，由此將粉粒狀銅形成為所謂的瘤狀銅之粗化方法。 As a method of roughening the surface by electroplating, for example, a roughening method generally performed by electroplating for a copper foil for printed circuit disclosed in Patent Document 7 is preferably used. In other words, after the powdery copper plating layer is formed by the so-called "baking", the "granular coating" is applied to the powdery copper plating layer so as not to damage the uneven shape, and a substantially smooth plating layer is deposited. The powdery copper is formed into a so-called roughening method of the knob-like copper.

作為利用氣相外延法進行的粗化方法，優選為利用濺射法或CVD法在未處理電解銅箔表面上形成由銅或銅合金等構成的主要成份為銅之薄膜之方法。 As a roughening method by a vapor phase epitaxy method, a method of forming a film of copper mainly composed of copper or a copper alloy or the like on the surface of an untreated electrodeposited copper foil by a sputtering method or a CVD method is preferable.

作為利用蝕刻法進行的粗化方法，可以採用利用物理蝕刻法或化學蝕刻進行的方法。另外，作為利用研磨法進行的粗化方法，可以採用利用砂紙進行的研磨或者利用噴砂法進行的研磨等。 As the roughening method by the etching method, a method using physical etching or chemical etching can be employed. In addition, as a method of using grinding The roughening method of the row may be a polishing using sandpaper or a polishing using a sandblasting method.

防銹處理包括無機類防銹處理或者有機類防銹處理。無機類防銹處理有鉻酸鹽處理。有機類防銹處理有苯並***處理、矽烷偶聯劑處理等，上述防銹處理可以單獨進行或者組合進行。 The anti-rust treatment includes an inorganic anti-rust treatment or an organic anti-rust treatment. The inorganic rust-proof treatment is chromate treatment. The organic rust-preventing treatment may be a benzotriazole treatment or a decane coupling agent treatment, and the rust-preventing treatment may be carried out singly or in combination.

鉻酸鹽處理使用含有重鉻酸離子之水溶液，無論是酸性還是鹼性都可，並且進行浸漬處理或陰極電解處理。另外，在該鉻酸鹽處理中，附著於銅箔上的物質係從六價鉻還原後之三價鉻之氧化物或氫氧化物。 The chromate treatment uses an aqueous solution containing dichromate ions, either acidic or basic, and is subjected to an immersion treatment or a cathodic electrolysis treatment. Further, in the chromate treatment, the substance adhering to the copper foil is an oxide or hydroxide of trivalent chromium which is reduced from hexavalent chromium.

通常藥品使用三氧化鉻、重鉻酸鉀、重鉻酸鈉等。 Usually, the medicine uses chromium trioxide, potassium dichromate, sodium dichromate and the like.

作為有機類防銹處理之苯並***類可列舉苯並***、甲基苯並***、氨基苯並***、羧基苯並***等，可在形成為水溶液後藉由浸漬處理或噴射處理來實施。 Examples of the benzotriazole which is an organic rust-proof treatment include benzotriazole, methylbenzotriazole, aminobenzotriazole, carboxybenzotriazole, etc., which may be subjected to immersion treatment after being formed into an aqueous solution or The blasting process is carried out.

矽烷偶聯劑存在含有環氧基、氨基、巰基、乙烯基之矽烷偶聯劑等多種，但是，只要使用與電極構成活性物質層之黏合性出色者即可，可在形成為水溶液或有機溶液後藉由浸漬處理或噴射處理等實施。 The decane coupling agent may be a plurality of decane coupling agents containing an epoxy group, an amino group, a thiol group, and a vinyl group. However, if it is excellent in adhesion to an electrode constituting the active material layer, it may be formed into an aqueous solution or an organic solution. Thereafter, it is carried out by immersion treatment, blast treatment, or the like.

經過以上處理後製成鋰離子二次電池負極集電體用銅箔。 After the above treatment, a copper foil for a negative electrode current collector of a lithium ion secondary battery was produced.

【實施例】 [Examples]

以下，根據實施例更加詳細地對本發明進行說明，但是，本發明並不限於此。 Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

<實施例1> <Example 1>

利用圖1所示之裝置製成電解銅箔。即，利用以旋轉之鈦輥11作為陰極且在其下側配置有DSA14的第一電解槽16，在鈦輥11與DSA14之間流入下述組成之硫酸銅-硫酸電解液13，並在鈦輥-DSA之間接通電流，從而製成厚度為6 μm的電解銅箔1。 An electrolytic copper foil was produced using the apparatus shown in Fig. 1. That is, the first electrolytic cell 16 in which the rotating titanium roller 11 is used as the cathode and the DSA 14 is disposed on the lower side thereof, and the copper sulfate-sulfuric acid electrolyte 13 having the following composition flows between the titanium roller 11 and the DSA 14, and is in the titanium. An electric current was applied between the rolls and the DSA to form an electrolytic copper foil 1 having a thickness of 6 μm.

H₂SO₄=20~200 g/L H ₂ SO ₄ =20~200 g/L

氯化物離子=1~60 ppm Chloride ion = 1~60 ppm

動物膠=1~30 ppm Animal glue = 1~30 ppm

溫度=30~70℃ Temperature = 30~70°C

電流密度：30~100 A/dm² Current density: 30~100 A/dm ²

該銅箔1之電沉積面(粗糙面)102之表面粗糙度為：Rz=2.1 μm、Ra=0.3 μm。 The surface roughness of the electrodeposited surface (rough surface) 102 of the copper foil 1 was Rz = 2.1 μm and Ra = 0.3 μm.

將該銅箔1引至第二輥12上，並使用組成與第一電解液相同之電解液18在光澤面側電沉積6 μm的銅，從而得到12 μm的銅箔2。在所述輥101面上電沉積銅後的面之粗糙度為：Rz=2.1 μm、Ra=0.3 μm，由此可得到兩面均呈「電沉積面」形狀之銅箔2。該銅箔之抗拉強度=352 MPa，延展率=6.4%。 The copper foil 1 was introduced onto the second roll 12, and 6 μm of copper was electrodeposited on the glossy side using an electrolytic solution 18 having the same composition as that of the first electrolytic solution, thereby obtaining a copper foil 2 of 12 μm. The roughness of the surface after electrodepositing copper on the surface of the roll 101 was Rz = 2.1 μm and Ra = 0.3 μm, whereby the copper foil 2 having the shape of "electrodeposited surface" on both sides was obtained. The tensile strength of the copper foil was 352 MPa, and the elongation rate was 6.4%.

另外，Rz係為JIS B 0601-1994中所述之十點平均粗糙度，Ra係為JIS B 0601-1994中所述之算術平均粗糙度。 Further, Rz is a ten point average roughness as described in JIS B 0601-1994, and Ra is an arithmetic mean roughness as described in JIS B 0601-1994.

接著，在5 g/L三氧化鉻溶液中以0.3 A/dm²之電流密度對該銅箔之兩面進行10秒鐘陰極電解，然後水洗並乾燥，由此制得電池用電解銅箔。 Next, the both sides of the copper foil were subjected to cathodic electrolysis for 10 seconds at a current density of 0.3 A/dm ² in a 5 g/L chromium oxide solution, and then washed with water and dried to prepare an electrolytic copper foil for a battery.

圖3係該電解銅箔之電子顯微鏡照片，圖3A係利用第一輥形成的電沉積面(粗糙面)之照片，圖3B係利用第二輥在第一輥的光澤面上電沉積銅後的面之照片。 3 is an electron micrograph of the electrolytic copper foil, FIG. 3A is a photograph of an electrodeposited surface (rough surface) formed by a first roll, and FIG. 3B is a second roller after electrodepositing copper on the shiny side of the first roll. Photo of the face.

可見銅箔之兩面側均呈「電沉積面」之形狀。 It can be seen that both sides of the copper foil have the shape of "electrodeposited surface".

此處所使用之銅電解液中的有機添加劑為動物膠。動物膠係可得到柱狀結晶之代表性有機添加劑。因此，如圖3A和圖3B所示，該電沉積面為具有凹凸之表面。 The organic additive in the copper electrolyte used herein is animal glue. Animal gums provide representative organic additives for columnar crystals. Therefore, as shown in FIGS. 3A and 3B, the electrodeposited surface is a surface having irregularities.

將上述電池用電解銅箔作為集電體，並在活性物質中使用平均粒徑為100 nm之矽類粒子，從而組裝成電池。 The above-mentioned battery electrolytic copper foil was used as a current collector, and ruthenium particles having an average particle diameter of 100 nm were used for the active material to assemble a battery.

關於負極電極，其係將矽類活性物質64%、乙炔黑粉末(AB)16%以及聚醯胺酸溶液20%混合調製成漿料，將該漿料塗敷在上述電解銅箔上，並將塗膜形成為大致均勻的薄片，然後乾燥並利用壓力機進行壓縮，從而使活性物質層緊密黏合於集電體上，進而進行減壓乾燥，由此製成試驗電極(負極)。然後，將該試驗電極沖裁成20φ，形成負極。 The negative electrode is prepared by mixing 64% of an anthraquinone active material, 16% of acetylene black powder (AB), and 20% of a polyamidonic acid solution into a slurry, and applying the slurry to the electrolytic copper foil, and The coating film was formed into a substantially uniform sheet, and then dried and compressed by a press, whereby the active material layer was closely adhered to the current collector, and further dried under reduced pressure to prepare a test electrode (negative electrode). Then, the test electrode was punched out to 20 φ to form a negative electrode.

將上述電極作為負極，將金屬鋰箔作為對極和參照極，將1.3 mol之LiPF₆/碳酸乙烯酯(EC)+碳酸甲乙酯(EMC)+碳酸二甲酯(DMC)(EC：EMC：DMC=2：5：3(體積比))溶液作為電解液，製成三極電池。 Using the above electrode as a negative electrode and a metal lithium foil as a counter electrode and a reference electrode, 1.3 mol of LiPF ₆ /ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + dimethyl carbonate (DMC) (EC: EMC) :DMC=2:5:3 (volume ratio)) The solution was used as an electrolyte to make a three-pole battery.

根據以下方法在25℃的溫度下對該試驗電池之負極進行了評價。 The negative electrode of the test cell was evaluated at a temperature of 25 ° C according to the following method.

充放電試驗方法： Charge and discharge test method:

充電速率計算 Charging rate calculation

根據試驗電極中的活性物質量如下計算出充電速率。 The charging rate was calculated as follows based on the mass of the active material in the test electrode.

Si：1 C=4,000 mAh/g Si: 1 C = 4,000 mAh/g

初次條件 Initial condition

充電：以0.1 C左右之電流恆流充電，在達到0.02 V(對Li/Li+)後以恆電位充電，在充電電流降低至0.05 C左右時結束充電。 Charging: Charging with a constant current of about 0.1 C, charging at a constant potential after reaching 0.02 V (for Li/Li+), and ending charging when the charging current is reduced to about 0.05 C.

放電：以0.1 C的電流恆流放電，在達到1.5 V時結束放電。 Discharge: A constant current discharge of 0.1 C was applied, and the discharge was terminated when 1.5 V was reached.

充放電循環條件 Charge and discharge cycle conditions

在實施了初次充放電試驗後，以相同的0.1 C左右之電流重複進行100次充放電。 After the initial charge and discharge test was performed, the charge and discharge were repeated 100 times with the same current of about 0.1 C.

負極集電體材料使用該電解銅箔的電極於充放電100次後之放電容量保持率顯示於表1中。 The discharge capacity retention ratio of the electrode for the negative electrode current collector using the electrode of the electrodeposited copper foil after charging and discharging for 100 times is shown in Table 1.

另外，循環後之放電容量保持率以下式表示。 In addition, the discharge capacity retention ratio after the cycle is expressed by the following formula.

(循環後之放電容量保持率%)=[(循環後之放電容量)/(最大放電容量)]×100 (Discharge capacity retention rate after cycle %) = [(discharge capacity after circulation) / (maximum discharge capacity)] × 100

<實施例2> <Example 2>

利用第一輥以與實施例1相同之條件製成厚度為8 μm的電解銅箔。將該銅箔引至第二輥上，並使用與第一輥相同之電解液在光澤面側電沉積4 μm之銅，從而得到12 μm之銅箔。 An electrolytic copper foil having a thickness of 8 μm was produced under the same conditions as in Example 1 using the first roll. The copper foil was introduced onto the second roll, and 4 μm of copper was electrodeposited on the glossy side using the same electrolyte as the first roll, thereby obtaining a copper foil of 12 μm.

該銅箔之電沉積面(粗糙面)之粗糙度為：Rz=2.1 μm、Ra=0.3 μm，在光澤面上電沉積銅後的面之粗糙度為：Rz=1.8 μm、Ra=0.2 μm。該銅箔之抗拉強度=346 MPa，延展率=6.7%。 The roughness of the electrodeposited surface (rough surface) of the copper foil is: Rz=2.1 μm, Ra=0.3 μm, and the roughness of the surface after electrodepositing copper on the shiny surface is: Rz=1.8 μm, Ra=0.2 μm . The copper foil has a tensile strength = 346 MPa and an elongation ratio of 6.7%.

圖4係該電解銅箔之電子顯微鏡照片，圖4A係利用第一輥形成的電沉積面(粗糙面)之照片，圖4B係利用第二輥在第一輥之光澤面上電沉積銅後的面之照片。 4 is an electron micrograph of the electrolytic copper foil, FIG. 4A is a photograph of an electrodeposited surface (rough surface) formed by a first roll, and FIG. 4B is a second roller after electrodepositing copper on the shiny side of the first roll. Photo of the face.

接著，在將該銅箔水洗後，與實施例1同樣地在三氧化鉻溶液中對兩面進行陰極電解，並在水洗後乾燥，從而製成電池集電體用電解銅箔。 Then, after the copper foil was washed with water, the both surfaces were subjected to cathodic electrolysis in a chromium trioxide solution in the same manner as in Example 1, and after washing with water, the film was dried to obtain an electrodeposited copper foil for a battery current collector.

在該電解銅箔上塗敷與實施例1相同之活性物質，並且利用相同方法進行試驗電池之製造和評價。將其結果一併記載於表1中。 The same active material as in Example 1 was applied to the electrolytic copper foil, and the production and evaluation of the test battery were carried out by the same method. The results are collectively shown in Table 1.

<實施例3> <Example 3>

利用以旋轉的鈦輥作為陰極且在其下側配置有DSA的第一輥，在鈦輥與DSA之間流入下述組成之硫酸銅-硫酸電解液，並在鈦輥-DSA之間接通電流，由此製成厚度為8 μm的電解銅箔。 Using a first roll in which a rotating titanium roll is used as a cathode and DSA is disposed on the lower side thereof, a copper sulfate-sulfuric acid electrolyte having the following composition flows between the titanium roll and the DSA, and a current is applied between the titanium roll and the DSA. Thus, an electrolytic copper foil having a thickness of 8 μm was produced.

H₂SO₄=20~200 g/L H ₂ SO ₄ =20~200 g/L

氯化物離子=1~60 ppm Chloride ion = 1~60 ppm

羥乙基纖維素=1~30 ppm Hydroxyethyl cellulose = 1~30 ppm

溫度=30~70℃ Temperature = 30~70°C

電流密度：30~100 A/dm² Current density: 30~100 A/dm ²

該銅箔之電沉積面(粗糙面)之粗糙度為：Rz=2.1 μm、Ra=0.3 μm。 The roughness of the electrodeposited surface (rough surface) of the copper foil was Rz = 2.1 μm and Ra = 0.3 μm.

將該銅箔引至第二輥上，並使用與第一輥不同之下述電解液在光澤面側電沉積4 μm的銅，從而得到12 μm的銅箔。由此可以得到在光澤面上電沉積銅後的面之粗糙度為：Rz=2.2 μm、Ra=0.3 μm之兩面均呈「電沉積面」形狀的銅箔。該銅箔之抗拉強度=330 MPa，延展率=7.0%。 The copper foil was introduced onto the second roll, and 4 μm of copper was electrodeposited on the glossy side using the following electrolyte different from the first roll, thereby obtaining a copper foil of 12 μm. Thus, it is possible to obtain a copper foil having a surface having a roughness of Rz=2.2 μm and Ra=0.3 μm on both sides of the electrodeposited surface. The copper foil has a tensile strength = 330 MPa and an elongation ratio of 7.0%.

H₂SO₄=20~200 g/L H ₂ SO ₄ =20~200 g/L

氯化物離子=1~60 ppm Chloride ion = 1~60 ppm

動物膠=1~30 ppm Animal glue = 1~30 ppm

溫度=30~70℃ Temperature = 30~70°C

電流密度：30~100 A/dm² Current density: 30~100 A/dm ²

圖5係該電解銅箔之電子顯微鏡照片，圖5A係利用第一輥形成的電沉積面(粗糙面)之照片，圖5B係利用第二輥在第一輥之光澤面上電沉積銅後的面之照片。 Fig. 5 is an electron micrograph of the electrolytic copper foil, Fig. 5A is a photograph of an electrodeposited surface (rough surface) formed by a first roll, and Fig. 5B is a second electrode after electrodepositing copper on the shiny side of the first roll. Photo of the face.

另外，此處所使用之銅電解液中的有機添加劑在第一輥時為羥乙基纖維素，在第二輥時為動物膠。羥乙基纖維素和動物膠兩者均係可得到柱狀結晶之有機添加劑。因此，如圖5A和圖5B所示，該電沉積面為具有凹凸之表面。 Further, the organic additive in the copper electrolytic solution used herein is hydroxyethyl cellulose in the first roll and animal glue in the second roll. Hydroxyethyl fiber Both the vegetarian and the animal glue are organic additives which can obtain columnar crystals. Therefore, as shown in FIGS. 5A and 5B, the electrodeposited surface is a surface having irregularities.

接著，在將該銅箔水洗後，與實施例1同樣地在三氧化鉻溶液中對兩面均進行陰極電解，並在水洗後乾燥，從而製成電池用電解銅箔。 Then, after the copper foil was washed with water, both surfaces were subjected to cathodic electrolysis in a chromium trioxide solution in the same manner as in Example 1, and after washing with water, the film was dried to obtain an electrolytic copper foil for a battery.

<實施例4> <Example 4>

利用第一輥以與實施例1相同之條件製成厚度為5 μm的電解銅箔。將該銅箔引至第二輥上，並使用與第一輥相同之電解液在光澤面側電沉積5 μm的銅，得到10 μm的銅箔。 An electrolytic copper foil having a thickness of 5 μm was produced by the same conditions as in Example 1 using the first roll. The copper foil was introduced onto the second roll, and 5 μm of copper was electrodeposited on the glossy side using the same electrolytic solution as the first roll to obtain a copper foil of 10 μm.

接著，藉由電鍍在該銅箔之表面上實施銅之燒鍍處理，從而形成粉粒狀銅鍍層。進而，在該粉粒狀銅鍍層上以不損壞其凹凸形狀之方式實施精密鍍銅(包鍍)，從而製成提高了粉粒狀銅與電解銅箔之黏合性之粗化電解銅箔。 Next, a copper plating treatment is performed on the surface of the copper foil by electroplating to form a powdery copper plating layer. Further, on the powdery copper plating layer, precision copper plating (coating) is performed so as not to damage the uneven shape, thereby obtaining a roughened electrolytic copper foil having improved adhesion between the powdery copper and the electrolytic copper foil.

按照最初兩面上之粉粒狀銅鍍層和包鍍之重量厚度分別為1 μm，銅箔之厚度最終變為12 μm之方式實施電鍍。 Electroplating was carried out in such a manner that the thickness of the powdery copper plating and the plating on the first two sides were 1 μm, and the thickness of the copper foil finally became 12 μm.

另外，銅箔表面粗化用之粉粒狀電鍍之條件、精密鍍銅(包鍍)之條件如下所示。 Further, the conditions for the powder-plated plating for roughening the surface of the copper foil and the conditions for precision copper plating (cladding) are as follows.

粉粒狀電鍍之條件： Conditions for powdered plating:

精密鍍銅(包鍍)之條件： Precision copper plating (coating) conditions:

該銅箔兩面之粗糙度為：Rz=2.6 μm、Ra=0.4 μm。該銅箔之抗拉強度=352 MPa，延展率=5.3%。 The roughness of both sides of the copper foil was: Rz = 2.6 μm and Ra = 0.4 μm. The tensile strength of the copper foil was 352 MPa, and the elongation rate was 5.3%.

<實施例5> <Example 5>

利用第一輥以與實施例1相同之條件製成厚度為7 μm的電解銅箔。將該銅箔引至第二輥上，並使用與第一輥相同之電解液在輥面側電沉積7 μm的銅，從而得到14 μm的銅箔。 An electrolytic copper foil having a thickness of 7 μm was formed under the same conditions as in Example 1 by the first roll. The copper foil was introduced onto the second roll, and 7 μm of copper was electrodeposited on the roll side using the same electrolytic solution as the first roll, thereby obtaining a 14 μm copper foil.

利用蝕刻處理將該銅箔之兩面的每一面除去1 μm。蝕刻處理使用MEC株式會社製造之CZ8101以噴射方式進行。蝕刻後之銅箔厚度為12 μm，銅箔兩面之粗糙度為：Rz=2.2 μm、Ra=0.3 μm。該銅箔之抗拉強度=340 MPa，延展率=5.1%。 Each side of both sides of the copper foil was removed by 1 μm by etching. The etching treatment was carried out by spraying using CZ8101 manufactured by MEC Corporation. The thickness of the copper foil after etching is 12 μm, and the roughness of both sides of the copper foil is: Rz=2.2 μm, Ra=0.3 μm. The tensile strength of the copper foil was 340 MPa, and the elongation rate was 5.1%.

<比較例1> <Comparative Example 1>

利用圖2所示之電解銅箔製造裝置，並利用以旋轉的鈦輥作為陰極且在其下側配置有DSA之輥，在鈦輥與DSA之間流入下述組成之硫酸銅-硫酸電解液，並在鈦輥-DSA之間接通電流，由此製成厚度為12 μm的電解銅箔。 An electrolytic copper foil manufacturing apparatus shown in Fig. 2 was used, and a copper sulfate-sulfuric acid electrolyte having the following composition was flowed between the titanium roller and the DSA by using a rotating titanium roll as a cathode and a DSA roller disposed on the lower side thereof. And a current was applied between the titanium roll-DSA, thereby producing an electrolytic copper foil having a thickness of 12 μm.

電解液組成和電解條件：Cu=50~150 g/L L Electrolyte composition and electrolysis conditions: Cu=50~150 g/L L

H₂SO₄=20~200 g/L H ₂ SO ₄ =20~200 g/L

氯化物離子=1~60 ppm Chloride ion = 1~60 ppm

動物膠=1~30 ppm Animal glue = 1~30 ppm

溫度=30~70℃ Temperature = 30~70°C

電流密度：30~100 A/dm² Current density: 30~100 A/dm ²

該銅箔之電沉積面(粗糙面)之粗糙度為：Rz=6.0 μm、Ra=0.7 μm，輥面之粗糙度為：Rz=1.5 μm、Ra=0.2 μm。 The roughness of the electrodeposited surface (rough surface) of the copper foil was Rz = 6.0 μm, Ra = 0.7 μm, and the roughness of the roll surface was: Rz = 1.5 μm and Ra = 0.2 μm.

圖6係該電解銅箔之電子顯微鏡照片，圖6X係電沉積面(粗糙面)之照片，圖6Y係光澤面之照片。 Fig. 6 is an electron micrograph of the electrolytic copper foil, Fig. 6X is a photograph of the electrodeposited surface (rough surface), and Fig. 6Y is a photograph of the glossy surface.

接著，在將該銅箔水洗後，與實施例1同樣地在三氧化鉻溶液中對兩面均進行陰極電解，並在水洗後乾燥，從而製成電池用電解銅箔。 Next, after the copper foil was washed with water, in the same manner as in Example 1, both surfaces were subjected to cathodic electrolysis in a chromium trioxide solution, and after washing with water, it was dried. It is made into an electrolytic copper foil for batteries.

此處所使用之銅電解液中的有機添加劑為動物膠，因此能夠得到柱狀晶。因此，如圖6X所示，該電沉積面(粗糙面)為具有凹凸之表面。另一方面，因為光澤面係與輥接觸之面，因此，如圖6Y所示，光澤面為條紋狀的平滑表面。 The organic additive in the copper electrolyte used here is animal glue, and thus columnar crystals can be obtained. Therefore, as shown in Fig. 6X, the electrodeposited surface (rough surface) is a surface having irregularities. On the other hand, since the glossy surface is in contact with the surface of the roll, as shown in Fig. 6Y, the shiny surface is a striped smooth surface.

在該電解銅箔上塗敷與實施例1相同之活性物質，並且利用相同方法進行試驗電池之製造和評價。將該結果一併記載於表1中。 The same active material as in Example 1 was applied to the electrolytic copper foil, and the production and evaluation of the test battery were carried out by the same method. The results are collectively shown in Table 1.

<比較例2> <Comparative Example 2>

利用以圖2所示電解製箔裝置之旋轉的鈦輥作為陰極且在其下側配置有DSA的輥，在鈦輥與DSA之間流入下述組成之硫酸銅-硫酸電解液，並在鈦輥-DSA之間接通電流，由此製成厚度為12 μm的電解銅箔。 A titanium oxide roll having a rotating titanium roll as shown in FIG. 2 as a cathode and having a DSA disposed on the lower side thereof, and a copper sulfate-sulfuric acid electrolyte having the following composition flowing between the titanium roll and the DSA, and titanium An electric current was applied between the rolls and the DSA, thereby producing an electrolytic copper foil having a thickness of 12 μm.

H₂SO₄=20~200 g/L H ₂ SO ₄ =20~200 g/L

氯化物離子=1~60 ppm Chloride ion = 1~60 ppm

羥乙基纖維素=1~30 ppm Hydroxyethyl cellulose = 1~30 ppm

溫度=30~70℃ Temperature = 30~70°C

電流密度：30~100 A/dm² Current density: 30~100 A/dm ²

該銅箔之電沉積面粗糙度為：Rz=4.1 μm、Ra=0.6 μm，輥面粗糙度為：Rz=2.2 μm、Ra=0.4 μm。 The electrodeposited surface roughness of the copper foil was: Rz = 4.1 μm, Ra = 0.6 μm, and the roll surface roughness was: Rz = 2.2 μm, and Ra = 0.4 μm.

圖7係該電解銅箔之電子顯微鏡照片，圖7X係電沉積面(粗糙面)之照片，圖7Y係光澤面之照片。 Fig. 7 is an electron micrograph of the electrolytic copper foil, Fig. 7X is a photograph of the electrodeposited surface (rough surface), and Fig. 7Y is a photograph of the glossy surface.

此處所使用之銅電解液中的有機添加劑為羥乙基纖維素，因此能夠得到柱狀晶。因此，如圖7X所示，該電沉積面為具有凹凸之表面。另一方面，因為光澤面係與輥接觸之面，因此，如圖7Y所示，光澤面為條紋狀之平滑表面。 The organic additive in the copper electrolytic solution used herein is hydroxyethyl cellulose, and thus columnar crystals can be obtained. Therefore, as shown in Fig. 7X, the electrodeposited surface is a surface having irregularities. On the other hand, since the glossy surface is in contact with the surface of the roll, as shown in Fig. 7Y, the shiny surface is a stripe-like smooth surface.

<比較例3> <Comparative Example 3>

利用以圖2所示電解製箔裝置之旋轉的鈦輥作為陰極且在其下側配置有DSA的輥，在鈦輥與DSA之間流入下述組成之硫酸銅-硫酸電解液，並在鈦輥-DSA之間接通電流，由此製成厚度為6 μm的電解銅箔。 A titanium oxide roll having a rotating titanium roll as shown in FIG. 2 as a cathode and having a DSA disposed on the lower side thereof, and a copper sulfate-sulfuric acid electrolyte having the following composition flowing between the titanium roll and the DSA, and titanium An electric current was applied between the rolls and the DSA, thereby producing an electrolytic copper foil having a thickness of 6 μm.

H₂SO₄=20~200 g/L H ₂ SO ₄ =20~200 g/L

氯化物離子=1~60 ppm Chloride ion = 1~60 ppm

3-巰基-1-丙烷磺酸鈉=0.5~10 ppm Sodium 3-mercapto-1-propane sulfonate = 0.5~10 ppm

羥乙基纖維素=1~30 ppm Hydroxyethyl cellulose = 1~30 ppm

低分子量明膠(分子量為3,000)=1~30 ppm Low molecular weight gelatin (molecular weight 3,000) = 1~30 ppm

溫度=30~70℃ Temperature = 30~70°C

電流密度：30~100 A/dm² Current density: 30~100 A/dm ²

該銅箔之電沉積面(粗糙面)粗糙度為：Rz=1.3 μm、Ra=0.3 μm，光澤面之粗糙度Rz=1.6 μm、Ra=0.4 μm。 The roughness of the electrodeposited surface (rough surface) of the copper foil was Rz = 1.3 μm, Ra = 0.3 μm, and the roughness of the shiny surface was Rz = 1.6 μm and Ra = 0.4 μm.

拍攝該電解銅箔之電子顯微鏡照片，圖8X：顯示電沉積面(粗糙面)，圖8Y：顯示光澤面。 An electron micrograph of the electrolytic copper foil was taken, and Fig. 8X: shows the electrodeposited surface (rough surface), and Fig. 8Y: showed a glossy surface.

按照最初兩面上的粉粒狀銅鍍層和包鍍的重量厚度分別為3 μm，銅箔之厚度最終變為12 μm之方式實施電鍍。 Electroplating was carried out in such a manner that the thickness of the powdery copper plating and the plating on the first two sides were 3 μm, and the thickness of the copper foil finally became 12 μm.

粉粒狀電鍍之條件： Conditions for powdered plating:

精密鍍銅(包鍍)之條件： Precision copper plating (coating) conditions:

該銅箔之電沉積面(粗糙面)粗糙度為：Rz=3.1 μm、Ra=0.4 μm，光澤面粗糙度為：Rz=3.7 μm、Ra=0.5 μm。該銅箔之抗拉強度=370 MPa，延展率=4.5%。 The roughness of the electrodeposited surface (rough surface) of the copper foil was Rz = 3.1 μm, Ra = 0.4 μm, and the gloss surface roughness was: Rz = 3.7 μm and Ra = 0.5 μm. The copper foil has a tensile strength = 370 MPa and an elongation ratio of 4.5%.

拍攝該電解銅箔之電子顯微鏡照片，圖9X：顯示電沉積面(粗糙面)，圖9Y：顯示光澤面。 An electron micrograph of the electrolytic copper foil was taken, and Fig. 9X: shows the electrodeposited surface (rough surface), and Fig. 9Y: shows the glossy surface.

在作為該銅箔之原箔的6 μm階段中，粗糙面電沉積面(粗糙面)之粗糙度小於光澤面。因此，在銅箔之表面上利用電鍍實施了銅之燒鍍處理後接著實施精密鍍銅(包鍍)從而形成粉粒狀銅鍍層之表面，即使在粉粒狀銅鍍層之條件設定為相同時，亦會受到原箔之粗糙度之影響，使電沉積面(粗糙面)之粗糙度小於光澤面。 In the 6 μm stage which is the original foil of the copper foil, the roughness of the rough surface electrodeposited surface (rough surface) is smaller than that of the shiny surface. Therefore, a copper plating treatment is performed on the surface of the copper foil by electroplating, followed by precision copper plating (coating) to form a surface of the powdery copper plating layer, even when the conditions of the powdery copper plating layer are set to be the same. It will also be affected by the roughness of the original foil, so that the roughness of the electrodeposited surface (rough surface) is smaller than that of the glossy surface.

接著，在將該銅箔水洗後，與實施例1同樣地在三氧化鉻溶液中對兩面均進行陰極電解，並在水洗後乾燥，從而製成電池集電體用電解銅箔。 Then, after the copper foil was washed with water, in the same manner as in Example 1, both surfaces were subjected to cathodic electrolysis in a chromium trioxide solution, and after washing with water, the film was dried to obtain an electrodeposited copper foil for a battery current collector.

如圖3~圖5所示，本發明之電解銅箔之兩面呈相同的表面形狀，以實施例1~5之電解銅箔為集電體且使用Si類活性物質的電極為負極電極製成之鋰離子二次電池如表1所示，其循環效率之降低程度小且性能出色。 As shown in FIG. 3 to FIG. 5, the two sides of the electrolytic copper foil of the present invention have the same surface shape, and the electrode made of the electrolytic copper foils of Examples 1 to 5 is used as a current collector and the electrode using a Si-based active material is made into a negative electrode. As shown in Table 1, the lithium ion secondary battery has a small degree of reduction in cycle efficiency and excellent performance.

可認為循環效率之降低程度小之理由如下，即，由本發明之圖3~圖5之實施例1~3之SEM照片可知，當凹凸之直徑小至2 μm~5 μm左右且凸起之高度低(Rz小)時，此處所使用之奈米尺寸的Si類活性物質進入凸起之穀底部份，即使重複進行充放電循環，亦可保持活性物質與集電體之接觸，因而循環效率之降低程度小。 The reason why the degree of reduction in cycle efficiency is small is considered to be as follows. That is, the SEM photographs of Examples 1 to 3 of Figs. 3 to 5 of the present invention show that the diameter of the concavities and convexities is as small as about 2 μm to 5 μm and the height of the projections. When low (Rz is small), the nano-sized Si-type active material used here enters the bottom portion of the valley of the bulge, and even if the charge-discharge cycle is repeated, the active material and the current collector can be maintained. Touch, and thus the degree of reduction in cycle efficiency is small.

另一方面，在圖6~圖9之比較例1、2、3中呈下述結果，即，電沉積面(粗糙面)側的循環效率之降低程度大，光澤面側的循環效率之降低程度同樣亦大，從而如表1所示無法滿足鋰離子二次電池之要求。 On the other hand, in Comparative Examples 1, 2, and 3 of Figs. 6 to 9, the following results were obtained, that is, the degree of reduction in the cycle efficiency on the electrodeposited surface (rough surface) side was large, and the cycle efficiency on the gloss side was lowered. The degree is also large, so that the requirements of the lithium ion secondary battery cannot be satisfied as shown in Table 1.

可認為粗糙面側循環效率之降低程度大的理由如下，即，由本發明之圖6、圖7之SEM照片可知，電沉積面(粗糙面)側的凹凸之直徑大至5 μm~10 μm左右且凸起之高度高(Rz大)。 The reason why the degree of reduction in the cycle efficiency on the rough surface side is large is considered to be as follows. The SEM photographs of Figs. 6 and 7 of the present invention show that the diameter of the irregularities on the side of the electrodeposited surface (rough surface) is as large as about 5 μm to 10 μm. And the height of the protrusion is high (Rz is large).

當電沉積面(粗糙面)為此種表面時，此處所使用之奈米尺寸之Si類活性物質未進入到凸起與凸起之間的穀底部份中，從而無法充分保持活性物質與集電體之接觸，因而循環效率之降低程度大。 When the electrodeposited surface (rough surface) is such a surface, the nano-sized Si-type active material used herein does not enter the valley bottom portion between the protrusion and the protrusion, thereby failing to sufficiently maintain the active material and The contact of the current collector is such that the cycle efficiency is reduced to a large extent.

可認為光澤面側循環效率之降低程度大的理由如下，即，光澤面雖然具有條紋狀凹凸但其係具有光澤之平滑面，因此，奈米尺寸之Si類活性物質與集電體之黏合強度弱，從而循環效率之降低程度大。 The reason why the degree of reduction in the luminous efficiency of the gloss side is large is considered to be as follows. That is, the glossy surface has a smooth surface with a streaky unevenness, and therefore, the bonding strength of the Si-type active material having a nanometer size to the current collector is obtained. Weak, so the cycle efficiency is reduced to a large extent.

另外，藉由圖9之電沉積在原箔表面上附著銅粒子之表面中，由於在銅箔表面上附著有直徑為1~5 μm左右之銅粒子，因此，此處所使用之奈米尺寸之Si類活性物質未進入到凸起之穀底部份中，從而無法充分保持活性物質與集電體之接觸，因而循環效率之降低程度大。 Further, in the surface on which the copper particles are adhered on the surface of the original foil by electrodeposition of FIG. 9, since copper particles having a diameter of about 1 to 5 μm are attached to the surface of the copper foil, the nanometer size Si used here is used. The active material does not enter the bottom portion of the valley of the bulge, so that the contact of the active material with the current collector cannot be sufficiently maintained, and thus the degree of reduction in cycle efficiency is large.

本發明之電解銅箔係兩面均藉由銅之電沉積形成之電解銅箔，其中，該電沉積面為柱狀晶之結晶組織。 The electrolytic copper foil of the present invention is an electrolytic copper foil formed by electrodeposition of copper on both sides, wherein the electrodeposited surface is a crystal structure of columnar crystals.

另外，本發明之電解銅箔係兩面均藉由銅之電沉積形成之電解銅箔，其中，該電解銅箔之第一表面係在輥面上電沉積結晶組織為柱狀晶之銅而形成的面，該第一表面之相反側之第二表面係在製成第一表面之後，在該第一表面之背側電沉積結晶組織為柱狀晶之銅而形成的面。 In addition, the electrolytic copper foil of the present invention is an electrolytic copper foil formed by electrodeposition of copper on both sides, wherein the first surface of the electrolytic copper foil is formed by depositing a crystal structure of a columnar crystal on the surface of the electrode. The surface of the second surface opposite to the first surface is formed on the back side of the first surface by electrodepositing a surface formed by a columnar crystal of copper on the back side of the first surface.

另外，本發明之電解銅箔，進一步利用電鍍法、氣相外延法、蝕刻法或者研磨法對兩面均藉由電沉積而形成且結晶組織為柱狀晶之電解銅箔表面進行了粗化。 Further, in the electrodeposited copper foil of the present invention, the surface of the electrodeposited copper foil formed by electrodeposition on both surfaces and having a crystal structure of columnar crystals is further roughened by a plating method, a vapor phase epitaxy method, an etching method, or a polishing method.

進而，本發明之電解銅箔，進一步利用電鍍法在兩面均藉由電沉積形成且結晶組織為柱狀晶之電解銅箔表面上形成由主要成份為銅之粒子構成的表面處理層。 Further, in the electrodeposited copper foil of the present invention, a surface treatment layer composed of particles mainly composed of copper is formed on the surface of the electrodeposited copper foil which is formed by electrodeposition and has a crystal structure of columnar crystals by electroplating.

另外，本發明之電解銅箔，進一步在兩面均藉由電沉積形成且結晶組織為柱狀晶之電解銅箔表面上形成有由粉粒狀銅鍍層和精密銅鍍層(包鍍層)形成之表面處理層，其中，該粉粒狀銅鍍層係藉由銅之燒鍍而形成者，該精密銅鍍層(包鍍層)係在該粉粒狀銅鍍層上以不損壞其凹凸形狀之方式形成者。 Further, in the electrolytic copper foil of the present invention, a surface formed of a powdery copper plating layer and a precision copper plating layer (coated layer) is formed on the surface of the electrolytic copper foil which is formed by electrodeposition and has a crystal structure of columnar crystals on both sides. In the treatment layer, the powdery copper plating layer is formed by baking of copper, and the precision copper plating layer (cladding layer) is formed on the powdery copper plating layer so as not to damage the uneven shape.

【產業上之可利用性】 [Industrial Availability]

本件銅箔可用作二次電池用銅箔，尤其是鋰離子二次電池負極集電體。 This copper foil can be used as a copper foil for a secondary battery, particularly a lithium ion secondary battery anode current collector.

Claims

一種鋰離子二次電池，包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液，其特徵在於：構成負極之所述集電體由電解銅箔構成，該電解銅箔之兩面藉由電沉積形成，該電沉積面為柱狀晶之結晶組織。 A lithium ion secondary battery comprising a positive electrode, a negative electrode having an electrode formed on the surface of the current collector to constitute an active material layer, and a nonaqueous electrolyte, wherein the current collector constituting the negative electrode is composed of an electrolytic copper foil The both sides of the electrolytic copper foil are formed by electrodeposition, and the electrodeposited surface is a crystal structure of columnar crystals.

一種鋰離子二次電池用集電體，其係構成包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液之鋰離子二次電池之所述負極之集電體，其特徵在於：該集電體由電解銅箔構成，該電解銅箔之兩面藉由電沉積形成，該電沉積面為柱狀晶之結晶組織。 A current collector for a lithium ion secondary battery, comprising: a positive electrode; a negative electrode having an electrode formed on an active material layer on a surface of a current collector; and a negative electrode of a lithium ion secondary battery of a nonaqueous electrolyte The current collector is characterized in that the current collector is made of an electrolytic copper foil, and both sides of the electrolytic copper foil are formed by electrodeposition, and the electrodeposited surface is a crystal structure of columnar crystals.

一種鋰離子二次電池負極集電體用電解銅箔，其係構成包括正極、負極以及非水電解液之鋰離子二次電池之所述負極集電體之電解銅箔，其特徵在於：該電解銅箔之兩面藉由電沉積形成，該電沉積面為柱狀晶之結晶組織。 An electrolytic copper foil for a negative electrode collector for a lithium ion secondary battery, which is an electrolytic copper foil of the negative electrode current collector of a lithium ion secondary battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte, characterized in that: Both sides of the electrolytic copper foil are formed by electrodeposition, and the electrodeposited surface is a crystal structure of columnar crystals.

一種鋰離子二次電池，包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液，其特徵在於：構成負極之所述集電體係藉由電沉積銅而形成之電解銅箔，該電解銅箔之第一表面係在輥面上電沉積結晶組織為柱狀晶之銅而形成的面，該第一表面之相反側之第二表面係在製成第一表面後，在第一表面之背側電沉積結晶組織為柱狀晶之銅而形成的面。 A lithium ion secondary battery comprising a positive electrode, a negative electrode having an electrode formed on the surface of the current collector to constitute an active material layer, and a nonaqueous electrolyte, wherein the current collecting system constituting the negative electrode is formed by electrodepositing copper And forming an electrolytic copper foil, the first surface of the electrolytic copper foil is a surface formed by electrodepositing a crystal structure into a columnar crystal copper on a surface of the roller, and a second surface opposite to the first surface After the first surface is formed, a surface formed by depositing a crystal structure into a columnar crystal of copper on the back side of the first surface is electrodeposited.

一種鋰離子二次電池用負極集電體，其係構成包括正極、在集電體之表面上形成有電極構成活性物質層之負極、以及非水電解液之鋰離子二次電池之負極集電體，其特徵在於：該負極集電體係藉由電沉積銅而形成之電解銅箔，該電解銅箔之第一表面係在輥面上電沉積結晶組織為柱狀晶之銅而形成的面，該第一表面之相反側之第二表面係在製成第一表面後，在第一表面之背側電沉積結晶組織為柱狀晶之銅而形成的面。 A negative electrode current collector for a lithium ion secondary battery, which comprises a negative electrode current collector including a positive electrode, a negative electrode having an electrode formed on the surface of the current collector to form an active material layer, and a lithium ion secondary battery having a nonaqueous electrolyte The body is characterized in that: the negative electrode current collecting system is an electrolytic copper foil formed by electrodepositing copper, and the first surface of the electrolytic copper foil is a surface formed by electrodepositing a crystal structure into a columnar crystal copper on a roll surface. The second surface on the opposite side of the first surface is formed on the back side of the first surface by electrodeposition of a crystal formed into a columnar crystal of copper on the back side of the first surface.

一種鋰離子二次電池之負極集電體用電解銅箔，其係構成包括正極、負極以及非水電解液之鋰離子二次電池之負極集電體用電解銅箔，其特徵在於：該電解銅箔係藉由電沉積銅而形成者，該電解銅箔之第一表面係在輥面上電沉積結晶組織為柱狀晶之銅而形成的面，該第一表面之相反側之第二表面係在製成第一表面後，在第一表面之背側電沉積結晶組織為柱狀晶之銅而形成的面。 An electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery, which is an electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte, characterized in that the electrolysis The copper foil is formed by electrodepositing copper. The first surface of the electrolytic copper foil is a surface formed by electrodepositing a crystal structure into a columnar crystal copper on a surface of the roller, and a second surface opposite to the first surface. After the surface is formed into the first surface, the surface formed by the crystal structure of the columnar crystal is electrodeposited on the back side of the first surface.

如申請專利範圍第3或6項所述之鋰離子二次電池之負極集電體用電解銅箔，其中，所述電解銅箔之表面係藉由電鍍法、氣相外延法、蝕刻法或者研磨法實施粗化處理之表面。 The electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery according to claim 3, wherein the surface of the electrolytic copper foil is by electroplating, vapor phase epitaxy, etching or The surface of the roughening treatment is carried out by a grinding method.

如申請專利範圍第3或6項所述之鋰離子二次電池之負極集電體用電解銅箔，其中，所述電解銅箔之表面係利用電鍍法電沉積有主要成份為銅之粒子之表面。 The electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery according to claim 3, wherein the surface of the electrolytic copper foil is electrodeposited by electroplating with particles mainly composed of copper. surface.

如申請專利範圍第3或6項所述之鋰離子二次電池之負極集電體用電解銅箔，其中，所述電解銅箔之表面係由粉粒狀銅鍍層和精密銅鍍層(包鍍層)形成之表面，所述粉粒狀銅鍍層係藉由銅之燒鍍處理而形成者，所述精密銅鍍層(包鍍層)係在該粉粒狀銅鍍層上以不損壞其凹凸形狀之方式而形成者。 The electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery according to claim 3, wherein the surface of the electrolytic copper foil is a powdery copper plating layer and a precision copper plating layer (coating layer) a surface formed by forming a powdery copper plating layer by a bronzing treatment of copper on which the fine copper plating layer (coating layer) is applied so as not to damage the uneven shape thereof And the formation.